1. Field of the Invention
The present invention relates to a small size zoom lens system, and an image pickup apparatus such as a compact digital camera in which the zoom lens system is used.
2. Description of the Related Art
In an image pickup apparatus such as a digital camera and a video camera, a high image quality, a high magnification, and a thinning of a lens frame have been sought. For example, a two-unit zoom lens system which includes a first lens unit having a negative refracting power and a second lens unit having a positive refracting power as described in Japanese Patent Application Laid-open Publication No. 2006-284790 has hitherto been known. This two-unit zoom lens system is advantageous for simplification of a drive mechanism, as the number of lens units to be moved at the time of zooming is two, which is small.
However, a need of making small an overall length of the zoom lens system with respect to an image plane size is becoming increasingly high. On the other hand, recently, an image pickup element which is capable of picking up a favorable image even when an angle of incidence of light rays incident on a surrounding portion in an image pickup area of an image pickup element, as disclosed in Japanese Patent Application Laid-open Publication No. 2006-351972 has been known.